I give up

I've been trying to turn my work into something that will permit me to quit my day job and it's just not working out. I feel that I do pretty good work. I sell some stuff sometimes. I never sell enough but I'm convinced that if every other person in the world would see my stuff, I would sell enough.

I cannot stand my day job but I must support a family of 5 (wife, twin daughters, and son). Let me say that again, I am ready to put a ****ing rasor to my wrist I hate my day job so much - and I am firmly and thoroughly trapped in it.

I really do think my photo stuff is pretty good. I'm really fed up. I am just so ****ing sick of this.

Don't despair - although it may feel like you are trapped at the moment there is always a way out. You just have to find it.
You need to work out a strategy so that you can work towards your goal. It won't happen overnight but it does turn your job into a means to an end rather than a millstone.
Let's start with where you want to end up. Do you want to make a living from just providing library photos, or do you want to work in a field like weddings and portraits?
Once you tell us that, then we can start offering serious useful advice.

I'm sorry you're feeling so low right now. Just going by the limited info I have from your post, it sounds like your day job is causing serious stress. I know you said you are trapped, and I think we've all felt like that at some point, but maybe focusing on how you can change that situation, more education, career change, etc will help. I've been using photography as a part time job and it's a nice balance. Maybe things will feel better if you can somehow find a full time job that isn't so horrid so that there isn't so much pressure to make the photography a living all at once.